Conveying systems dispense material from a hopper to a pressurized convey line through a feed device. Pressure in the convey line can make it difficult to dispense material from the hopper into the convey line. Continuous injection or flow of material to the pressurized convey line limits downtime or interruptions in material delivery. Multiple or redundant systems have been employed to provide continuous material flow to a pressurized convey line. Multiple or redundant systems increase costs and maintenance. The above discussion provides a general introduction and background for the application and is not intended to be used as an aid for determining the scope of the claimed subject matter or invention nor limit the scope of the claimed subject matter.